Reaction and Immunogenicity of Freeze-dried Live Attenuated Rubella Vaccine Prepared with Virus Strain at Different Passages

Objective To study the reactinogenicity and immunogenicity of rubella virus strain BRD Ⅱ at the 30 th ,31 st and 32 nd passages.Methods The reactinogenicity and immunogenicity were observed in 277 children and 141 young women,both negative in serum rubella HI antibody.The children,or women,were divided into 3 groups and inoculated with the rubella vaccine prepared with strain BRD Ⅱ at the 30 th ,31 st and 32 nd passages respectively.Results The serum rubella HI antibody positive conversion rates of 3 groups of children were 97.8%,98.9% and 98.9%,and the GMTs of them were 278.7,23.7.1 and 292.9 respectively.However,in the 3 groups of young women,the positive conversion rates were 94.8%,97.5% and 100.0%,and GMTs were 101.5,132.9 and 96.6 respectively.No significant difference were observed in the HI antibody positive conversion rates or GMTs induced by the vaccine prepared with the 3 passages of virus.Conclusion The biological characters of rubella virus strain at passages 30 to 32 are stable.All the passages can be used for the production.